174 FRAGMENTS OF SCIENCE. 
A map of the district, with the parallel roads shown, is 
annexed. 
LITERATURE OF THE SUBJECT. 
THOMAS PENNANT. A tour in Scotland. Vol. iii. 1776, p. 394. 
JOHN MAcCuLLOCH. On the Parallel Roads of Glen Roy. Geol. 
Soc. Trans, vol. iv. 1817, p. 314. 
THOMAS LAUDER DICK (afterward SIR THOMAS DICK-LAUDER, 
Barrt.). On the Parallel Roads of Lochaber. Edin. Roy. Soc. 
Trans. 1818, vol. ix. p. 1. 
CHARLES DARWIN. Observations on tlie Parallel Roads of Glen Roy, 
and of the other parts of Lochaber in Scotland, with an attempt 
to prove that they are of marine origin. Phil. Trans. 1839, vol. 
cxxix. p. 39. 
SIR CHARLES LYELL. Elements of Geology. Second edition, 
1841. 
Louis AGASSIZ. The Glacial Theory and its Recent Progress 
Parallel Terraces. Edin. New Phil. Journal, 1842, vol. xxxiii. 
p. 236. 
DAVID MILNE (afterward DAVID MILNE-HOME). On the Parallel 
Roads of Lochaber; with Remarks on the Change of Relative 
Levels of Sea and Land in Scotland, and on the Detrital Deposits 
in that Country. Edin. Roy. Soc. Trans. 1847, vol. xvi. p. 395. 
ROBERT CHAMBERS. Ancient Sea Margins. Edinburgh, 1848. 
H. D. ROGERS. On the Parallel Roads of Glen Roy. Royal Inst. 
Proceedings, 1861, vol. iii. p. 341. 
THOMAS F. JAMIESON. On the Parallel Roads of Glen Roy, and 
their Place in the History of the Glacial Period. Quart. Journal 
Geol. Soc. 1863, vol. xix. p. 235. 
SIR CHARLES LYELL. Antiquity of Man. 1863, p. 253. 
REV. R. B. WATSON. On the Marine Origin of the Parallel Roads 
of Glen Roy. Quart. Journ. Geol. Soc. 1865, vol. xxii. p. 9. 
SIR JOHN LUBBOCK. On the Parallel Roads of Glen Roy. Quart. 
Journ. Geol. Soc. 1867, vol. xxiv. p. 83. 
CHARLES BABBAGE. Observations on the Parallel Roads of Glen 
Roy. Quart. Journ. Geol. Soc. 1868, vol. xxiv. p. 273. 
JAMES NICOL. On the origin of the Parallel Roads of Glen Roy. 
1869. Geol. Soc. Journal, vol. xxv. p. 282. 
JAMES NICOL. How the Parallel Roads of Glen Roy were formed. 
1872. Geol. Soc. Journal, vol. xxviii. p. 237. 
MAJOR-GENERAL SIR HENRY JAMES, R. E. Notes on the Parallel 
Roads of Lochaber. 4to. 1874. 
discourse here reported by the model just described, constructed 
under the supervision of my assistant, Mr. John Cottrell. Glen 
Gluoy with its lake and road and the cataract over its col; Glen Roy 
and its three roads with their respective cataracts at the head of Glen 
Spey, Glen Glaster, and Glen Spean, were all represented. The 
successive shiftings of the barriers, which were formed of plate glass, 
brought each successive lake and its corresponding road into view, 
while the entire removal of the barriers caused the streams to flow 
down the glens of the inod.elas they flow down the real glens of to- 
day. 
